Pump lock



Sept. 20, 1949. R. ST. J. QRR

PUMP LOCK Filed Dec. 18. 1944 INVENTOR. ROBERT 5x1 0 9 RrTo/EWE vs invention is concerned is commonly Patented Sept. 20, 1949 PUMP LOCK Application December 18,

. This invention relates to a pump lock and has for its main object the provision of a simple, quick releasable and reliable means for locking the pump cylinder and plungerthat is reciprocable thereinin telescopically collapsed position against accidental withdrawal of the plunger.

The particular type of pump with which this used by forest service men in the fighting of fires, in which an inner cylinder carrying a handle and nozzle at one end, is reciprocable within an outer-cylinder that is connected by a hose with a source of liquid, such liquid generally being in a tankcarried by knapsack straps on the back of the operator. When-not in actual use, the pump, which iSordinarily between two and three feet in length, may bereleasablysecured on top of the tank behind the back of the-operator and in a position extende ing horizontally across the tank. 3 g

In the carrying .of the pump onthe tank, considerable difficulty has been experienced by reasonv of the tendency of, the plunger to move gradually outwardly of the pump cylinder-to its extended position. Strenuous activity of the wearer may expedite this of such movement of which the operator may be unaware is that the pump is constantly in danger of being damagedand in many instances pumps have been completely incapacitated and rendered useless atcritical times. Also, on occasions, the operators have been seriously injured dueto unexpected catchin of the extended plunger ,on trees, shrubs, boulders or on the sides of cliffs.

The problem of overcoming the above objections involves many considerations, principal= amon which are reliability, durability, ease of manipulation and simplicity. I The instant invention solves said objections and in addition to the above-mentioned requirements it is economical to makeand does any degree with the operation of the pump nor does it, by overcoming one hazard, give rise to another. 7

Other objects and advantages will appear in the drawings and description.

- In the drawings,

Fig. l is an elevational view of a pump tank with the pump releasably secured thereon in inoperative position Fig. 2 is an enlarged part-sectional and partelevational view ofthe handle, nozzle and the means for releasably locking the pump cylinder and plunger together. Thecylinder and plunger are shown unlocked and separated in this view.v

movement. One result not interfere in s and with thepump collapsed.

' liquid stroke. I

Robert St. Orr, San Francisco, Calif.

1944, Serial No. 568,688

sciaimsi (01. 103-202) Fig. 3 is a sectional view taken along line 3- -3 of Fig. 2. I

Fig; 4 is a sectional view taken along line 4-4 of Fig. 2.

Fig. 5 isa fragmentary elevational view of the locking elements of the plunger and cylinder in locked position. I

In detail, the pump of this invention is the type generally called knapsack pump-tanks or backpumps, and which have been employed for about twenty-five yearsinthe control of grass, brush and forestfires by-the UnitedStates ForestService and other agencies. Also such pumps are adapted to use sprays in pest control. The pump itself in each unit is tubular and is generally releasably held in generally U-shaped spring clips I on top of a knapsack tank 2 (Fig. 1), the latter-having straps 3 for securement of the tank on the'back of the operator. A flexible hose 4 connects one end of the pump with the tank. The contents of the tank may 'be any desired according to the purposefor which it is used. As a common size of these pumps is capable of throwing a stream about forty feet vertically or horizontally, it is 'seen that the 'unit is very eflicient in the suppression and control of incipient fires, spot fires, mop-up work, snag fires, pole-line fires, etc.

The pump. itself comprises anouter pump cylinder; 5 having a conventional hoseconnection-"at one end for securement in the end-oi the hose 4'that is'opposite the end of the latter that is secured to tank 2. This hose is of suificientlength-so that the operator may detach the pump from the tank and swing it into pumping position, at either side of the body without removing the tank from his back.

A tubular plunger 6 is reciprocable within --the cylinder 5, and projects from the-end of said cylinder that isopposite hose 4 when said plunger is at the'limit of its stroke inwardly into cylinder 5, which isthe collapsed position of the pump as distinguished from its extended position .in which the plunger is at the limit of its outward A tubular handle I coaxial with plunger 6 encloses the projecting end portion of the latter. Said handle is secured to said projecting end by any suitable means and a relatively short end of the plungertube projects from the outerend of the handle, or the end that is opposite cylinder 5,. for securement of a nozzle 8 to such end.

The overall length of the pump from the nozzle to hose 4 whenthe pump is in collapsed position on thetank-z is preferably about 26 inches and specifically illustrate one means i6r of cylinder 5 opposite hose 4 carriee a=eaekifig=" gland through which the tplunger extends and normally this gland has the usual hexagon head for screwing it against the packing teat-settle between the gland and -a seat held in place by afi' aii ifiiilai ifiwaidly "-nireaeweiege I 0 fol' i'i ied in cylinder 5. v

' n1 *th presm intesnenpa paekmgfigland: I I is provided, but the head 52 projects fiaiige an y} outwii lilyfbfrtlie "ides of c'yliiifler 5 add irad is for-hied with-a raidi'ally' out- Wardly opening recess I3 in each of t'vt d-ofipdsite side's'tiiei oififigm a 'IKfid or insane-Ener ise n pam iiig glalid diameter as indicated se ene-nee witn'in w'hfe issecured'tne 'iierinheraI 0 age sexier asner 23- that eitte'nds yi d1 frdiifsa d grceveto'thepluriger tli Stufi eri' uIe 'I 5' andspaced :fiiovement outwardly of Handle or cylinder 5 are so rotated as to bring handle" will automatically mg-relationship Tor actuation of the plunger for tiaraine itt'et a rad 4 through recesses I3 on the head I2 of the packing gland H when said recesses and lugs are lined up, thus permitting the head I2 to pass into the outer end of the barrel I9 to a position between lugs 21 and said side 28 of flange 22 against the resistance of spring 2|. When the head I2 is in this position, a fractional rotation of the cylinder 5 and handle 1 relatively will bring the head behindsthe lugs 21 and then upon release "bf ftheiicylihdr 5" or handle; the -h'act I2 will be 2|- against lugs 27 and 6 will be locked against cylinder 5 until the yieldably held by spring said handle and plunger the lugs,21 to recesses I3 when the plunger and be released from lockpumping.

"Asseen in Fig. 5, when the pump cylinder and ndle are locked together, there is no projecti """i' other element tllat inigl it acideiit- "b'zi'c't a a Nor ng from *one' end of the mtnateemprisesacylinre to the endbf 'said handle e fbrnre'dwitarr-open end Cyl n r and brojeetingtm 32:11:9 cam/army projecting headeecured to the en of said. cylinder ad? e'nt said-barrel,- seau'iaaa teineesaaaai with 1 rel and of a diameter less-than bf th said cyli in the 'emi of saidbarr' adjaeent'said' head in eluding: a spring 'iirg'ed elementapositioned' for yieldable eirgaigenrent"with sai'c l he'ad wlien within said barrel' ingi'said head in said barre liensaidield ger is-at 'said' one efidafsaidstrok and 'embenon to be yieldably urged by said element when said head is in engagement with said element.

2. In a pump that has a tubular handle, plunger and main cylinder in coaxial alignment with the plunger reciprocable in said cylinder and the handle projecting from one end of the cylinder, the improvement that comprises a cylindrical barrel secured to the end of said handle adjacent said cylinder formed with an open end directed toward said cylinder and projecting toward the latter, a packing nut around said plunger secured to the end of said cylinder adjacent said barrel having a radially outwardly projecting head, said head being coaxial with said barrel and of a diameter less than that of the barrel adapting it to be enclosed within said barrel at one end of the stroke of said plunger, means within the end of said barrel adjacent said head including a spring urged element positioned for yieldable engagement with said head when the latter is within said barrel for releasably holding said head in said barrel when said plunger is at said one end of said stroke and a member on said barrel against which said head is adapted to be yieldably urged when said head is in engagement with said element.

3. A look for releasably securing a tubular pump plunger within a main pump cylinder against accidental withdrawal of the plunger from said cylinder comprising a tubular handle by said element N coaxial with said plunger and cylinder and projecting from on said las one end of the latter, a head secured t mentioned end of said cylinder through which said plunger is reciprocable, a cylindrical barrel projectin from said handle toward said cylinder formed with an open end directed toward said cylinder for receiving said head therein, a coil spring in said barrel coaxial therewith and adapted to yieldably engage said head when the latter is in said barrel for tending to force said head out of said barrel, means within said barrel at the end thereof adjacent said cylinder for holding said head in said barrel, said means including spaced lugs adapted to engage said head and said head being formed with recesses adapted to pass said lugs upon rotation of said head and barrel relatively for permitting said head to be withdrawn from said barrel when said lugs and recesses are in registration.

ROBERT ST. J. ORR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

